Tag: solusvm

Through our research and implementation of many Xen environments, it has become necessary to develop a reliable and secure method for backing up our Xen instances that are mounted on Logical Volumes (LVM).

The underlying problem is that the logical volume is usually a live file system that cannot be directly mounted / backed up or imaged safely.

We have written a script that processes all running Xen logical volumes, creates a snapshot of the volume and through that snapshot , uses dd to image the snapshot to another server over ssh.

You would be surprised at how well these dd images compress. Piping dd to bzip2 then to ssh to receive the image produces a very substantial compression ratio.

The initial trouble was writing the logic in the script to properly go through each Xen LV , create the snapshot, image and then remove the snapshot. Obviously extensive testing had to be completed to ensure reliability and proper error reporting.

This script should work with any 3rd party Xen control panel implementation (HyperVM, FluidVM, SolusVM to name a few). They all use the same underlying technology / framework. Since our script is a simple bash / shell script, it will run on any linux based system with little modification.

If you are using a LV for another purpose on the same box, it is probably a good idea to modify the script to ignore that so it doesn’t inadvertently get backed up.

Before implementing the script, it is probably a good idea to go through the motions manually just to see how it performs :

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